To present invention relates generally to sealless steel strapping tools, and more particularly to combination strap tensioning and sealing tools.
Sealless strapping tools are known generally and used widely to seal overlapping strap portions tensioned about a load without the use of a separate sealing member that is clamped about the overlapping strap portions. In sealless metal strapping tools, it is known generally to seal the overlapping strap portions with a punch and die assembly.
The SPC-3431 sealless steel strapping tool made by ITW Signode, for example, comprises a feed wheel disposed on a trailing end of a base plate that tensions an upper strap portion by drawing the strap portion over an underlying strap portion disposed and retained on the base plate. After tensioning, a plurality of dies are moved sequentially toward and into engagement with overlapping strap portions supported on a punch on the base plate to interlockingly fasten the overlapping strap portions. During the sealing operation, the feed wheel maintains tension on the overlapping strap portions engaged by the punch and die assembly to set the joint formed thereby. After sealing, the tensioned upper strap portion is severed by a strap cutter disposed between the punch and feed wheel. The dies and cutter are actuated by corresponding cams disposed on a rotating shaft, thereby controlling the timing of the sealing and cutting operations. The SPC-3431 tool is designed for tensioning and sealing 3/4 inch width strap, which is a relatively light gauge strap that is severed easily. The strap cutter of the SPC-3431 tool severs the strap while it is under tension by merely scoring it, rather than cutting fully therethrough. The strap cutter in the SPC 3431 tool however is not effective at severing heavier gauge strap, for example strap widths greater than 1 inch or so.
The CH-4632 sealless steel strapping tool made by ITW Orgapack comprises a feed wheel disposed on a leading end of a base plate that tensions an upper strap portion by pushing the strap portion over an underlying strap portion disposed and retained on the base plate. After tensioning, a plurality of jaw-like dies are actuated in cooperation with a punch to fasten the overlapping strap portions. The upper strap portion in the CH-4632 tool, however, is not maintained under tension during the sealing operation by virtue of the location of the feed wheel on the leading end of the base plate. The feed wheel in the CH-4632 tool is disengaged manually from the strap after sealing the overlapping strap portions, and more particularly after the jaws are released therefrom. The CH-4632 also comprises an angled strap cutter located on the trailing end of the base plate. The angled strap cutter is capable of cutting relatively heavy gauge strap, for example strap widths greater than 1 inch, and is operable when the strap is not under tension.
The present invention is drawn toward advancements in the art of sealless strapping tools for tensioning and sealing overlapping strap portions.
An object of the invention is to provide novel sealless strapping tools and methods therefor that overcome problems in the art.
Another object of the invention is to provide novel sealless strapping tools and methods therefor that are economical.
A further object of the invention is to provide novel sealless strapping tools and methods therefor for tensioning and sealing strap, especially heavier gauge steel strap.
Another object of the invention is to provide novel sealless strapping tools and methods therefor that form robust sealless joints having relatively low profiles with minimal strap deformation.
A more particular object of the invention is to provide novel sealless strapping tools and methods therefor comprising generally a feed wheel for engaging and tensioning overlapping strap portions, a strap sealing member engageable with overlapping strap portions to form a joint therebetween, a lifting cam engageable with the strap sealing member to disengage the strap sealing member from the overlapping strap portions, a release cam engageable with a pivotal link to disengage the feed wheel from the strap portion before the lifting cam fully disengages the strap sealing member therefrom.
These and other objects, aspects, features and advantages of the present invention will become more fully apparent upon careful consideration of the following Detailed Description of the Invention and the accompanying Drawings, which may be disproportionate for ease of understanding, wherein like structure and steps are referenced generally by corresponding numerals and indicators.